1. Technical Field
The present invention relates to a printing apparatus which transports a medium that is a printing target.
2. Related Art
A printer which is an example of a printing apparatus has a driving roller which transports a medium to a printing portion, and a plurality of driven rollers which are supported to be rotated respectively to one end side and another end side of one roller shaft and transport the transported medium with interposed between the driving roller and the driven roller by being rotated while pressing the medium on the driving roller.
In such a printer, it is possible to hold a revolving shaft of the driving roller and a revolving shaft of the driven roller in parallel by setting a form of a hole which is provided in the driven roller, in which the roller shaft is insertable, as a taper form in which the inner diameter is small in a center portion with respect to a shaft direction and becomes larger accompanying movement to both ends (for example, JP-A-2007-168961).
However, in a printer in the related art, in a case where a plurality of driven rollers are rotatably supported by one roller shaft, there are cases in which, for example, at both end portions in a width direction which intersects with a transport direction of a medium, out of the plurality of driven rollers, a driven roller between which and a driving roller the medium is interposed and a driven roller between which and a driving roller the medium is not interposed are mixed.
In such a case, since it is possible to hold the revolving shaft of the driven roller and the revolving shaft of the driving roller in parallel by the driven roller on which a hole is set in a taper form, pressing force that is applied to the medium of the driven roller which interposes the medium is able to be a larger pressing force than pressing force that is applied to the medium of the driven roller when all of a plurality of driven rollers interpose the medium. As a result, in a case where the plurality of driven rollers are attached to one roller shaft, there is a problem in that load which presses on the medium is not uniform and roller transfer scratches and nip marks are generated on the medium.
Note that, such a problem is not limited to a printer, and is generally common in a printing apparatus which interposes the medium and transports the medium to the printing portion.